Operating device for an electric switch comprising a push-button

ABSTRACT

An operating device having a rotatable crank drive which can be actuated by repeatedly pressing and releasing a knob or push-button. The push-button is thus alternately fixed in an operating position, i.e. the out position, and a locking position, i.e. the pressed-in position. A rotatable locking ring which can be axially displaced in an elastic manner and the body of the operating device include crank or link elements which are alternately distributed around the circumference, and in which the knob or push-button can be securely locked in a precise position.

This is a nationalization of PCT/DE02/01740 filed May 15, 2002 andpublished in German.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an operating device for a flush operating knobwith a locking device for the axial locking and unlocking of theoperating knob that is extendable under spring load by means of a linkguide, especially for the rotary switch of an automobile.

2. Description of the Related Art

It is common to flush-mount rotary knobs, such as those for theadjustment of brightness of lighting devices, in the instrument panel,and to release them from their home position by means of a simple pushof the knob in order to activate the operating knob. The knob is thenflush again by simply pushing it in, and locked in this position inorder to hamper any unintentional activation and adjustment.

Generally, such devices, such as those according to DE 4330502 A, areprovided with a stationary link component, in the cardioid of which alaterally traveling link pin, which is connected to the spring-loadedoperating knob, engages in such a way that the axial position of theoperating knob changes cycles by means of simply pressing between twodifferent stroke positions. All stops and guides are embodied on thebody, which appropriately must be designed in a complex and stablemanner.

SUMMARY OF THE INVENTION

The present invention is based on the task of increasing locking safety,and improving the bearing of the movable components of the operatingdevice. This task is solved by means of an operating device for a flushoperating knob with a locking device for the axial locking and unlockingof the operating knob that is extendable under spring load by means of alink guide, especially for the rotary switch of an automobile, in whichthe link guide is embodied as a multiple toothed, circumferential linkdrive, and the body of the operating device, and a locking ring that isaxially fixed and pivoted on the operating knob, have successivelyarranged, circumferentially distributed link elements in which theoperating knob can be axially locked.

Such a rotatory link drive generally has push button switches, whichchange the switching position in gradual cycles, whereby the actualadjustment of the switch is directly activated by pressing the push knobonce or several times. A rotating link component is gradually rotated ina defined manner. The same is kinematically connected to activeswitching elements. In this way, different switching positions can berealized in the various rotary positions of the link component.

The uses of such a drive for the mere purpose of locking and unlockingaccording to the invention has the advantage that a multitude of supportpositions can be created along the circular track at the stationary linksurfaces, on which the multiple link elements, which are assigned to thepush knob, are supported on a broad basis with a correspondingly highinput tension. This causes the push knob to be safely fixed in itsheight position and its axial angular position, without requiring anexact guide inside of the body for this purpose. The lateral buckling ofthe push knob is thereby reliably avoided. The exterior side of the knobcan be maintained in a center position in an opening of the instrumentpanel without any lateral offset. By means of the large support andgliding panes of the link drive, materials of low strength and improvedgliding properties can be utilized.

Advantageous further embodiments of the invention include a locking ringhaving at least three of the movable link elements equally distributedacross its circumference which are supported in the locking position onthe fixed link elements of the body. This embodiment fixes the push knobin a manner that is safe from buckling.

According to further embodiments, the fixed link elements are attachedat an essentially hollow-cylindrical wall of the body radially facingtoward the interior, with the movable link elements of the locking ringprotruding radially toward the exterior and engaging into the fixed linkelements. Additionally, the fixed link elements may be embodied as upperlongitudinal ligaments offset from corresponding lower longitudinalligaments having frontal accumulation chamfers that face each other, thewidth of the upper longitudinal ligaments each corresponding to thewidth of the channels embodied between the lower longitudinal ligamentsand vice versa. These embodiments result in a simple, stable, and easyto produce design, whereby an interior molded component can be embodiedof two molded inserts that are divided lateral in the direction of theaxis.

The present invention may further be embodied such that the fixed linkelements of the body continuously extend to an exterior body edge of thehollow-cylindrical wall. The operating device can be attached to anassembly area in an instrument panel in its locked position, and theaxial spring-loaded operating knob in its unlocked position can berushed via a stop shoulder against a collar-like stop of the instrumentpanel. According to this embodiment, the push knob can be supported freeof clearance in its extended state under input tension at a definedheight position on the instrument panel, without the body having to beprecisely fixed on the instrument panel. This simplifies theconfiguration of the operating device, as well as its assembly inside ofthe instrument panel. This procedure is benefited by the fact that thepush knob can be anchored particularly safely in its pushed-in positionwith the aid of the multiple link elements so that the risk of anyunintentional unlocking with parts possibly catapulting off isnegligible.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment example of the invention is illustrated in the drawings,and is explained in further detail as follows.

FIG. 1 shows a longitudinal section through an operating device withcircular distributed link elements.

FIG. 2 schematically shows a partial contact arrangement of the linkelements according to FIG. 1 in various positions of a movement cycle.

FIG. 3 depicts in greater detail the function of the movable linkelements according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

According to FIG. 1, an operating device 1 has a central, axially fixedrotor 2 for driving a not illustrated rotary instrument that ispositioned underneath. The rotor is equipped with exterior longitudinalnotches 3, into which a bonnet-shaped push knob 4 with at least onecatcher 5, which protrudes into the interior, engages in an axiallyrelocatable and pivot-proof manner. On the bottom side of the push knob4, a multitude of axially protruding, circular distributed snap or latchhooks 6 are attached, which face the exterior, and on which a lockingring 7 is axially fixed and pivoted.

The rotor 2 is received in a cylinder-shaped body 8, on the interiorwall of which circumferentially distributed longitudinal ligaments 9 aremolded, which are embodied in a center section as fixed link elements 10of a rotatory link drive. The locking ring 7 has cam-like movable linkelements 11 that protrude toward the exterior in a circulardistribution, which engage between the fixed link elements 10, andtogether with the same, form the link drive. The longitudinal ligaments9 are interrupted in the center section, and release a ring-shapedcircumferential track 16 for the movable link elements 11. At a lowerbottom 12 of the body 8, a circumferential cam track is molded with cams13 that reach toward the top. At this height, the rotor 2 is pivot-proofand axially relocatably surrounded by a latch ring 14 with latch cams 15that protrude toward the bottom, which engage between the cams 13 in aratchet-like manner. A coil pressure spring 23 is rigged between thelower latch ring 14 and the upper latch ring 6, which pushes the latchring 14 toward the bottom, and the push knob 4 toward the top with acollar-like stop 20 against a stop shoulder 22 of an instrument panel 21indicated by semi-colon lines.

In the position shown, the push knob 4 is pushed out of the flush latchposition indicated by semi-colon lines into an operating position, inwhich it may be grabbed by the hand and adjusted. This adjustmentis—under the ratchet effect of the latch ring 14—transferred to therotor 2, and from the rotor, for example, to a not illustrated rotarypotentiometer for the adjustment of the luminous intensity.Subsequently, the push knob 4 can be relocated into the area of thecircumferential track 16 by picking up the circularly fixed locking ring7.

According to FIG. 2, the fronts of the longitudinal ligaments 9 thatface each other have accumulation chamfers 17, which are aligned withcorresponding counter chamfers of the trapeze-shaped movable linkelements 11 of the locking ring 7 in such a way that the same arerelocated into the same direction when the accumulation chamfers 17 arepushed. The longitudinal ligaments 9 arranged above the circumferentialtrack 16 are offset and arranged at a clearance with respect to thebottom ones so that the movable locking elements 11 are safely rotatedinto the contact range of the respective next fixed locking element 10by successively pushing and releasing the push knob 4.

Narrower and broader channels 18 are successively released between theupper longitudinal ligaments 9 as the movable link elements 11, which,in the broader ones can be relocated to the upper operating position,and which can rest at the narrower ones in the locking position 19. Thedifferent intermediate positions are marked by the link elements 11indicated by the semi-colon lines, the movement track of which isindicated by the movement arrows.

In connection with FIG. 3, the function of the movable link elements 11is explained in more detail. For purposes of simplicity in explanation,the inner side of the cylinder-shaped body 8 is illustrated as being aplane wall.

The longitudinal ligaments 9 are connected to the cylinder-shaped body8, and the movable link elements 11 are connected to the locking ring 7(as shown by the dotted line) and protrude in the direction of thecylinder-shaped body 8.

When the locking ring 7 and the link elements 11 are pushed down, asshown by the arrow A1, the link element 11; is moved downwards until itengages at the chamfer 17′ of the ligament 9′ at the lower side of thetrack 16. This position is shown by broken lines. Thereby, the linkelement 11′ and the locking ring 7 are rotated in the direction of thearrow A2.

When the locking ring 7 and the link element 11′ are released, the linkelement 11′ moves upward in the direction of the arrow A3 until itengages at the chamfer 17″ of ligament 9″ at the upper side of the track16. Thereby, the link element 11′ and the locking ring 7 are rotated inthe direction of the arrow A4. In this way the locking ring 7 is rotatedwith each alternate and successive engagement of the link elements 11with the upper and lower chamfers 17.

The invention being thus described, it will be apparent that the samemay be varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be recognized by one skilled in the art areintended to be included within the scope of the following claims.

1. An operating device for a flush operating knob that is axially lockedand unlocked under spring load, for a rotary switch of an automobile,comprising: a multiple toothed, circumferential link drive, in which abody of the operating device, and a locking ring that is axially fixedand pivoted on the operating knob have successively arranged,circumferentially distributed link elements in which the operating knobis axially lockable.
 2. The operating device according to claim 1,wherein the locking ring has at least three movable link elements thatare equally distributed across its circumference, and which aresupported in a locking position on fixed link elements of the body. 3.The operating device according to claim 1, wherein fixed link elementsare attached at an essentially hollow-cylindrical wall of the bodyradially facing toward an interior of said body, and that the movablelink elements of the locking ring protrude radially toward an exteriorto engage into the fixed link elements.
 4. The operating deviceaccording to claim 1, wherein fixed link elements on said body areembodied of upper longitudinal ligaments and, offset therefrom, of lowerlongitudinal ligaments with frontal accumulation chamfers that face eachother, a width of the upper longitudinal ligaments each corresponding toa width of channels embodied between the lower longitudinal ligaments,and vice versa.
 5. The operating device according to claim 1, whereinfixed link elements of the body continuously extend to an exterior bodyedge of a hollow-cylindrical wall, said operating device beingattachable to an assembly area in an instrument panel with said knob inits locked position, and said axially spring-loaded operating knob inits unlocked position being pushable via a stop shoulder against acollar-like stop of the instrument panel.
 6. An operating device for arotary switch with a flush operating knob that is extendable underspring load, comprising: a body having a plurality of fixed linkelements circumferentially distributed on an inner surface thereof; anda locking ring fitting within said body and being axially fixed andpivoted on said operating knob, said locking ring having successivelyarranged, circumferentially distributed movable link elements thereonthat cooperate with said fixed link elements to form a multiple toothedcircumferential link drive for axially locking and unlocking saidoperating knob.
 7. The operating device according to claim 6, whereinthe locking ring has at least three movable link elements that areequally distributed across its circumference and supported in a lockingposition on fixed link elements of the body.
 8. The operating deviceaccording to claim 6, wherein said body has an essentiallyhollow-cylindrical wall with said fixed link elements thereon whichradially face toward an interior of said body, said movable linkelements of the locking ring protruding radially toward an exterior toengage into said fixed link elements.
 9. The operating device accordingto claim 8, wherein said fixed link elements of the body continuouslyextend to an exterior body edge of said hollow-cylindrical wall.
 10. Theoperating device according to claim 6, wherein said fixed link elementson said body include upper longitudinal ligaments and, offset therefrom,lower longitudinal ligaments with frontal accumulation chamfers thatface each other, a width of each upper longitudinal ligamentcorresponding to a width of a respective channel between the lowerlongitudinal ligaments, and vice versa.
 11. The operating deviceaccording to claim 6, wherein said operating device is attachable to anassembly area in an instrument panel with said knob in its lockedposition, and said axially spring-loaded operating knob in its unlockedposition is pushable via a stop shoulder against a collar-like stop ofthe instrument panel.